Vertical cavity surface emitting lasers, which have become quite well known in the past few years, are formed in a variety of configurations. However, the basis for the laser in virtually all configurations is an active area sandwiched between two mirror stacks. To activate the laser it is necessary to drive current through the mirror stacks and the active area. This is generally accomplished by placing a first electrode across the mirror stack at one end of the laser and a second electrode across the mirror stack at the other end of the laser. One of the electrodes generally defines a central opening therethrough for the emission of light.
For maximum efficiency, it is necessary that the major portion of the current is coextensive with the lasing, or light emission area. Any current outside the lasing area is either wasted or produces lasing which is wasted. Further, the central opening through one of the electrodes should be very close to the same size as the lasing area, otherwise some of the light produced within the laser will not be able to exit the laser but will simply be reflected back into the laser and dispersed. Thus, there is a need to coordinate the application of current to the laser with the lasing area and the emission output.